I do notice other women's boobs...but mostly about bra sizing. I worked in Victoria's Secret for a couple years, mostly in the bra department so it became second nature to notice and help women find the right bra size. I do notice that women who are pregnant/BF'ing tend to go up in size but I don't always put the two together early on in the pregnancy. But I'd say I can usually notice it as a clue that a woman is pregnant. Like another pp said, it's amazing how many women wear a bra that's too small/big and complain about being uncomfy but then won't change to a bra that fits correctly! I do my best not to interject this opinion of mine on other women however...most ppl find it creepy LOL